Automatic liquid dispenser for flush tanks and the like

ABSTRACT

A liquid dispenser for discharging metered amounts of liquid into a flush tank in response to the rise and fall of the tank liquid level. The dispenser comprises a container having a discharging neck portion provided with external screw threads, and having a captive screw cap which has internal cooperable screw threads and additionally has an internal annular captivating bead spaced from its threads. The open end of the container neck includes a resilient sealing lip which is engageable by a sealing ring portion of the cap when the latter is fully threaded in or down whereby the cap constitutes a sealed closure for the container. As the cap is unscrewed, its captivating bead is forced past the first of two spaced-apart annular beads on the container neck, which now operate to restrict axial movement of the cap between extended and retracted positions. For both of these positions the cooperable screw threads of the assemblage are free of each other. The cap has annular walls which define an air chamber providing buoyancy when the cap is immersed in a liquid. With the container inverted and the cap assembled thereto, the latter is urged between extended and retracted positions in response to changes in the level of the liquid in the tank. Responding to a fall in the liquid level, the cap moves by gravity to its extended position and a recess therein receives a predetermined quantity of liquid from the container. As the tank level rises, the cap is slowly urged by buoyant force to its retracted position whereby liquid contained in the recess is displaced therefrom, thus effecting a dispensing of the liquid into the tank. In the retracted position of the cap, the bead thereof is held in abutment with one of the spacedapart neck beads to form a seal and thus prevent leakage of the container contents into the tank until the occurrence of the next change in tank liquid level.

United States Patent Bryan 1 Dec. 18, 1973 AUTOMATIC LIQUID DISPENSER FOR FLUSH TANKS AND THE LIKE James W. Bryan, 15 Madison Springs Dr., Madison, Conn. 06443 Filed: May 19, 1972 Appl. No.: 255,056

Inventor:

US. Cl. 4/227, 4/228, 248/360, 222/67 Int. Cl A47k 13/30 Field of Search 222/56, 67, 64, 546, 222/562, 563, 57; 4/223, 231, 226, 227, 228; 248/359, 360, 311

References Cited UNITED STATES PATENTS 10/1972 Mack et a1 9/1967 Pannutti 4/227 X 9/1971 Ardoto et a1. 222/546 8/1910 Garnet 4/227 Primary Examiner-Robert B. Reeves Assistant Examiner-Norman L. Stack, Jr. Attorney-H. Gibner Lemann et al.

ABSTRACT threads and additionally has an internal annular captivating bead spaced from its threads. The open end of the container neck includes a resilient sealing lip which is engageable by a sealing ring portion of the cap when the latter is fully threaded in or down whereby the cap constitutes a sealed closure for the container. As the cap is unscrewed, its captivating bead is forced past the first of two spaced-apart annular beads on the container neck, which now operate to restrict axial movement of the cap between extended and retracted positions. For both of these positions the cooperable screw threads of the assemblage are free of each other. The cap has annular walls which define an air chamber providing buoyancy when the cap is immersed in a liquid. With the container inverted and the cap assembled thereto, the latter is urged between extended and retracted positions in response to changes in the level of the liquid in the tank. Responding to a fall in the liquid level, the cap moves by gravity to its extended position and a recess therein receives a predetermined quantity of liquid from the container. As the tank level rises, the cap is slowly urged by buoyant force to its retracted position whereby liquid contained in the recess is displaced therefrom, thus effecting a dispensing of the liquid into the tank. in the retracted position of the cap, the bead thereof is held in abutment with one of the spaced-apart neck beads to form a seal and thus prevent leakage of the container contents into the tank until the occurrence of the next change in tank liquid level.

22 Claims, 15 Drawing Figures PMENIEMEB 1 8 ms WEE? 2 BE 4 PATENIED DEC 18 @975 SHEET 3 0F 4 I I I/I/I/ AUTOMATIC LIQUID DISPENSER FOR FLUSH TANKS AND THE LIKE BACKGROUND This invention relates to automatic liquid dispensing devices, and more particularly to dispensers of the type adapted to discharge liquid from a container into a flush tank in response to the rise and fall of the liquid level therein. In the past, a number of such liquid dispensers have been proposed and constructed. Generally with these constructions a container has a threaded closure cap which is engageable with a cooperable threaded neck portion of the container to provide a seal thereof during storage and shipping. In some cases the neck portion has had a hollow threaded insert, constituting one portion of a valve wherein the threaded cap, when removed, could be inverted and forcibly engaged with the bore of the insert to form therewith another valve portion. The cap usually had some form of air chamber to provide buoyancy, although frequently this chamber was not strictly sealed but merely consisted of an inverted cup configuration whereby the buoyancy was provided by trapped air.

These prior liquid dispensers had a number of distinct drawbacks. For one thing, following removal of the cap (such as after storage or shipping) there was necessary the reinsertion or assemblage to the threaded insert of the neck portion. Frequently this method of operation was not an obvious one to the unskilled user such as a housewife, and often difficulty was encountered. Secondly, in most cases a large number of molded parts was required (usually at least three or four separate pieces) particularly where a separate insert, threaded into the neck was employed. Moreover, the air chamber that was needed, was often disposed near the bottom of the movable valve member, and thus the buoyant force existed at a low float-center, which aggravated any tendency for the cap to become cocked or tilted. Such tendency frequently resulted in binding or jamming of the movable valve member. Also, in cases where an open float chamber was employed, the valve cap had to be submersed in a nearly vertical position to avoid permitting trapped air in the chamber to escape and be displaced by water whereby it would adversely reduce the float chamber buoyancy.

SUMMARY The above drawbacks and disadvantages of prior liquid dispensers are overcome by the present invention, which has for an object the provision ofa novel and improved automatic dispenser which is especially simple in its construction, which has an absolute minimum number of parts that can be easily and inexpensively fabricated as molded pieces, and which is moreover particularly simple to assemble and to use, thus enabling an unskilled person to readily install and use the device. A related object of the invention is to provide a liquid dispenser as above, which comprises a one-part unitary cap that is normally held captive on the container neck and that acts both as a sealing closure for the container during storage and shipping, and as a metering and float valve to dispense predetermined quantities of liquid into a flush tank in response to the rise and fall of tank fluid contained therein. The above objects are accomplished by a novel combination of container having a neck portion provided with external screw threads and, spaced therefrom, a pair of separated annular beads disposed closely adjacent the container body. A unique screw cap which has a captivating bead and internal screw threads provides a sealed closure for the container when the threads are fully engaged. The captivating bead is disposed adjacent the cap threads and can be forced past the first of the annular neck beads as the cap is unscrewed, so as to straddle the latter. The engagement of the captivating bead with each of the annular neck beads defines extended and retracted positions of the cap, respectively. The cap further has a sealed air chamber which provides a buoyant force thereto when it is immersed in liquid.

The cap when assembled to the inverted container suspended ina flush tank thus constitutes a float valve which, in its extended position, permits a predetermined quantity or charge of .liquid from the container to flow into a recessed portion of the cap. As the cap is urged to its retracted position by a rising tank liquid, the charge therein is displaced and flows between the container neck portion and cap wall, and thence into the tank. In the fully retracted position of the cap, the captivating bead is urged by buoyant force against the innermost neck bead of the container and thus provides a seal of the container contents until the next succeeding tank cycle.

In the accompanying drawings, which illustrate the preferred embodiments of the invention:

FIG. 1 is a side elevational view of the liquid dispenser of the present invention, illustrating the container and screw cap assembled thereto.

FIG. 2 is a fragmentary vertical sectional view of the dispenser showing the threaded screw cap tightly engaging the corresponding threads on the container neck, thus sealing the latter against leakage for storage or shipping.

FIG. 3 is a view similar to that of FIG. 2, illustrating the cap in a position hereinafter referred to as the retracted position, wherein the threads thereof are disengaged from the container neck threads.

FIG. 4 is a view similar to that of FIGS. 2 and 3, illustrating the cap in a position hereinafter referred to as the extended position, wherein the threads thereof are also disengaged from the container neck threads.

FIG. 5 is a vertical sectional view of the threaded screw cap.

FIG. 6 is a bottom plan view of the screw cap of FIG. 5.

FIG. 7 is a fragmentary side elevational view of the container, particularly illustrating the neck portion thereof.

FIG. 8 is a sectional view taken along the line 8-8 of FIG. 7.

FIG. 9 is an end elevational view of the container.

FIG. 10 is a bottom plan view of the container and a slider clamp piece engaging the transverse bottom wall thereof, illustrating the clamp piece as suspending the container from the edge of a flush tank, in a typical installation.

FIG. 11 is a plan view of the container clamp piece.

FIG. 12 is a perspective view of the container clamp piece.

FIG. 13 is a vertical sectional view of a molded, onepiece screw cap and closure member illustrating another embodiment of the invention.

FIG. 14 is a top plan view of the alternate form of screw cap.

FIG. is a vertical sectional view of a further modified screw cap of the invention.

Referring first to FIG. 1 there is illustrated a liquid dispenser for flush tanks generally designated by the numeral 10, comprising a container 12 constituted as a bottle having a top discharging neck portion 14, a body portion 6, and comprising a captive screw cap 18 constituting a stopper thereof. The neck portion 14 is provided with a longitudinal bore 20 which communicates with the interior of the container, and has external screw threads 22. In FIG. 2, the captive screw cap 18 has internal screw threads 24 which are cooperable and engageable with the external threads 22 of the neck portion.

In accordance with the present invention, there are provided cooperable stop means disposed on the cap and container neck portion for restricting the axial movement of the cap between retracted and extended positions, said positions being illustrated respectively in FIGS. 3 and 4. The stop means comprises a pair of spaced-apart annular beads 26 and 28 on the neck portion 14 of the container, and an internal annular captivating bead 30 disposed on an annular guide portion 32 'of the cap 18. In FIG. 2, there is further illustrated a cooperable means on the cap and neck portion for sealingly closing the latter when the cap 18 is fully threaded thereon, comprising a resilient annular sealing lip 34 adjacent the open end of the container neck, and an annular ring-like sealing portion 36 on the cap 18 adjacent the threads 22.

Further, in accordance with the present invention there is provided novel floatation means on the cap 18, defining a sealed float chamber when the cap is inverted and immersed in the liquid of a flush tank, for automatically shifting the cap from its extended position (FIG. 4) to its retracted position (FIG. 3) in response to a rising level of the liquid. The said float chamber comprises outer and inner annular walls 38, 40 respectively, and a transverse wall 41, all defining an outer annular chamber 42 in the cap surrounding the neck portion of the container. Also, an annular wall 44 and a transverse wall 46 define an inner chamber 48 which is loosely receivable in the longitudinal bore 20 of the neck portion of the container.

The transverse wall 41 of the cap is of circular configuration and can optionally be molded as a separate piece. It is provided with a depending annular flange 43 having a bead 45, which is adapted to be sealingly received in a groove 47 in the annular wall 38 of the screw cap 16 and to be held captive thereby.

Referring now to FIGS. 9-12, the container 12 has a transverse bottom wall 50 disposed oppositely to the neck portion 14, and can be constituted of flow-molded plastic or other suitable resilient material. As provided by the invention, the wall 50 of the container has a groove 52 extending transversely from one side of the container 12 to the other, the groove having opposite undercut side walls 53 and 54, and the container side walls have recesses 55 and 55a respectively, communicating with the groove 52. A slider clamp piece 56, illustrated in FIGS. 11 and 12, having a flat body portion 57 and a pair of extremities 58 and 59 is slidably received in the groove 52. The extremities 58 and 59 can be accommodated respectively in the recesses 55a and 55. The clamp piece can be constituted of formed sheet metal or molded plastic substance. The side walls 53, 54 of the groove 52 are yieldable so as to enable the body portion 57 of the clamp piece 56 to be forced broadside into the groove and retained by the undercut portions of the side walls thereof. As illustrated in FIG. 10 the extremity 59 of the clamp piece is engageable with the wall of the recess 55 when the clamp piece is slid to the position shown, wherein the extremity 58 is disposed away from the opposite container side wall. The extremity 59 of the clamp piece is disposed at an acute angle with respect to the body portion 57 as illustrated in FIG. 12, such that the tip of the extremity engages the wall of the recess 55.

FIG. 10 illustrates a typical installation of the container 12 when suspended from a support member such as the wall of a flush tank. It will be noted that the length of the body portion 57 of the clamp piece is roughly equal to the width of the container or bottle 12, the width being measured along the groove 52. By such an arrangement, when the dispenser is not being used, as during shipping or storage, the clamp piece 56 can be conveniently slid to a position whereby neither of the extremities S8 or 59 extends or protrudes substantially beyond the container side walls. At such time as the dispenser is ready for use, the clamp piece 57 can be simply and easily slid to the position illustrated in FIG. 10. The depth of the recess 55 is thus seen to be commensurate with the spacing between the extremity 58 and the adjacent side wall of the container when the first extremity 59 engages the wall of the recess 55.

The operation of the improved liquid dispenser can now be readily understood. The container 12 is filled (at the manufacturers facilities) with the liquid intended to be dispensed (detergent, deodorant, disinfectant, etc.). Screw cap 18 is then assembled onto the neck portion 14 by gently forcing the internal annular bead 30 of the cap past the external screw threads 22 and annular bead 26. The neck portion 14 is preferably constituted of yieldable plastic substance, and the screw threads 22 and annular beads 26 and 28 can yield inwardly under external forces. At approximately the point where the cap bead 30 begins to engage the annular neck bead 28, the corresponding screw threads 24 and 22 of the cap and neck portions are almost but not quite brought into engagement. The cap 18 is now in the position illustrated in FIG. 3. The cap 18 can now be gently urged further in the same direction to force the cap bead 30 past the neck head 28, at which point the cap and neck threads 24 and 22 respectively become engaged, and the cap 18 can now be screwed fully onto the neck, to the position illustrated in FIG. 2. In this position, the resilient annular sealing lip 34 engages the annular ring-like sealing portion 36 of the cap, thus constituting cooperable means on the cap 18 and and neck portion 14 for sealingly closing the latter when the cap is fully threaded thereon. The dispenser may thus be stored and shipped without danger of leakage with the cap fully threaded onto the neck as illustrated in FIG. 2.

The liquid dispenser can be readily installed for use in existing flush tanks with a minimum of time and effort. The clamp piece 56 is slid to the position illustrated in FIG. 10, to enable it to be suspended from the support member or wall 60 of the flush tank. The container 12 and captive screw cap are now inverted such that the neck portion 14 is facing downwardly, and the screw cap slowly unscrewed. As this is done, the cap annular bead 30 will become engaged with the bead 28 of the neck portion 14. At this point the cap threads 24 and neck threads 22 are still partially engaged, so that further unscrewing of the cap will force the cap bead 30 past the neck bead 28, whereupon the threads will become just disengaged. The cap will now be in the position illustrated in FIG. 3 (the retracted position). In this position, the cap bead 30 and neck bead 28 are closely engaged and thus provide a seal of the neck portion 14. If the cap 18 is now released, it will fall (by gravity) to its extended position (indicated in FIG.4. As this occurs, liquid from the inverted container 12 will, by gravity, fill the recess 64 in the cap until the level therein reaches the level of the annular sealing lip 34 of the neck. The flow into the cap will thereupon cease, since the flow of air into the container which is necessary to displace the liquid being removed therefrom is cut off when the liquid level in the cap reaches the sealing portion 34 of the neck. The dispenser can now be installed in the flush tank in its inverted position as illustrated in FIGS. 4 and 10. As this is done, the cap 18 will become submerged, and-the buoyancy provided by the chambers 42 and 48 will urge the cap 18 to the retracted position, indicated in FIG. 3. As the cap is moved from its extended to its retracted position, the liquid which heretofore filled recess 64 will become displaced by the annular walls of the neck portion 14, and thus will be forced out through the space between the annular wall 40 of the cap and neck portion 14. It is to be especially noted that, in accordance with the present invention, the annular bead 26 has a relieved surface comprising a plurality of flats 66, 68, 70 and 72, (FIGS. 7 and 8) which provide passages in the form of clearance spaces between the relieved surface bead 26 and the cap 18 when the latter is out of the retracted position, and thus the bead 26 is unlike the bead 28 which is continuous and can sealingly engage the cap bead 30 when the cap is in the retracted position.

Referring again to FIG. 7, the neck portion 14 of the container has longitudinally extending bearing ribs, three of which are shown and designated 75, disposed between the spaced apart neck beads 26 and 28. These bearing ribs are engageable with the cap bead 30 disposed on the inner wall 40, and thus constitute an advantageous guide means for preventing tilting of the cap 18 when the latter moves between its extended and retracted positions. By the above arrangement, any tendency toward cocking or tilting of the cap along its path of travel is greatly minimized, and friction between the cap and neck is also minimized due to the relatively small areas thereof in direct contact with one another.

It can now be understood that under normal circumstances when the flush tank is full, the screw cap 18 will be submerged in the tank liquid, and the cap will be urged to its retracted position as illustrated in FIG. 3 by a buoyant force due to the captive air in the chambers 42 and 48. A predetermined volume of liquid will occupy chamber 64 of the cap 18. In the retracted position, no dispensing of the container liquid occurs, since the cap bead 30 is sealingly engaging the neck bead 28 of the container. At such time as the tank liquid begins to fall below the level of the retracted cap, the cap will be urged by gravity to follow the falling level until it reaches the extended position (FIG. 4). During this transition, air which was drawn into the recess 64 from the flush tank will displace liquid from the container, which liquid fills the recess 64 until the level therein reaches the level of the sealing lip 34 of the neck 14, at which time no further liquid from the container will flow because the path of displacement air for the container is now blocked by the liquid level in the cap recess. Assuming that the tank has emptied, and the liquid level therein now begins to rise, the cap 18 will eventually experience a buoyant force which urges it from its extended position (FIG. 4) to its retracted position (FIG. 3). During this transition, a quantity of dispensing liquid equal in volume to the quantity that entered chamber 64 during the previous transition (from the retracted position to the extended position) will be displaced from the cap recess 64 and travel in the spaces between relieved surfaces 66, 68, 70 and 72 of the bead 26 of the annular wall of the cap 18, in the direction of the arrows in FIG. 4, and thus out into the tank. It is noted that the liquid cannot be forced back into the container through the bore 20 during this transition because such a flow would require a net displacement of air out of the container, which clearly could not occur under these circumstances.

From the above it is clear that liquid from the container is dispensed into the tank only during the transition of the cap from its extended position (FIG. 4) to its retracted position (FIG. 3). The quantity of liquid dispensed is dependent upon the spacing between the beads 26 and 28. A large spacing therebetween will permit a large volume of liquid to enter the recess 64 during the transition of the cap from its retracted position to its extended position. A correspondingly large quantity will then be displaced by the container neck 14 and dispensed into the tank during the transition from the extended to the retracted position of the cap 18. Thus, the spacing between the beads 26 and 28 constitutes a metering control for the dispenser.

An alternate form of screw cap is illustrated in FIGS. 13-14, wherein the cap is constituted as a single molded piece, and designated generally by the numeral 18a. The screw cap has internal screw threads 24a, an annular ring-like sealing portion 360 adapted to be sealingly engaged by the resilient annular sealing lip 34 of the container neck portion 14 when the cap is fully threaded thereon, a pair of annular walls 38a and 40a and a transverse wall 41a. The transverse wall 41a has a depending flange 43a which is formed as best illustrated in FIG. 14, and the latter has a bead 45a which is adapted to be sealingly received in the groove 47a of the annular wall 380. The wall 41a is fastened to the annular cap wall 38a by means of an integral hinge 39a. Thus, when assembled, the transverse wall 41a and annular walls 38a and 40a define an outer air chamber 42a, and annular wall 44a and transverse wall 46a also define an inner air chamber 48a. Annular wall 40a has an internal annular bead 30a which functions in a manner identical to that of the first-described screw cap 18.

A third form of screw cap 18b, considered the preferred form, is illustrated in FIG. 15. The cap is provided with internal screw threads 24b, annular walls 38b and 40b, and a transverse wall 41b having substantially the configuration of a disc, all of said walls defining a closed air chamber 42b which provides a buoyant force to the cap when it is immersed in liquid. The cap is provided with a resilient annular sealing lip 36b which is adapted to engage the annular ring-like sealing portion 34 of the container neck 14. The cap also has an internal annular bead 30b which can preferably be integral with the transverse wall 41b. Transverse wall 41b is further provided with an annular groove 74 which receives the edge portion 76 of the wall 40b, and

a shoulder portion 78 which closely and sealingly abuts the edge of annular wall 38b.

There are a number of advantages in the above constructions. First, the present invention employs a single screw cap as both a sealing closure for the container to prevent leakage during storage and shipping, and a metering and float valve to dispense predetermined quantities of liquid from the container into a flush tank. Thus, the number of separate parts required is kept to an absolute minimum. Second, the operation and use of the dispenser is extremely simple, due to the fact that the screw cap is held captive and merely requires turning movement relative to the container to ready the dispenser for use, without the necessity of removing the cap and reinserting it in an inverted position as has been the case in prior dispensers. Third, when the dispenser is suspended in a tank, substantial portions of the air chambers 42 in FIGS. 34, 42a in FIG. 13 and 42b in FIG. 15 are disposed high in relation to the mass center of the respective cap. By the above arrangement, the buoyant force which raises the cap to its retracted position acts through a high point on the cap, and thus the cap is pulled by the buoyant force rather than being pushed thereby, this minimizing any tendency for cocking or tilting of the cap during the transition from its extended position to its retracted position.

From the above it can be seen that l have provided a novel liquid dispenser which is simple in construction, reliable in operation and can be readily installed and activated by unskilled personnel whereby it represents a distinct advance and improvement in the liquid dispensing art.

Variations and modifications are possible without departing from the spirit of the invention.

1 claim:

1. A liquid dispenser for flush tanks and the like, comprising in combination:

a. an inverted container having a bottom discharge neck portion provided with a longitudinal bore which communicates with its interior, said neck portion having external screw threads,

b. a captive screw cap constituting a stopper, said cap being adapted for loose movement on the neck portion, said cap having internal screw threads cooperable and engageable with the external threads of the container neck portion,

c. cooperable stop means disposed on said screw cap and container neck portion for restricting axial movement of the cap between extended and retracted positions on the neck portion wherein for both said positions the screw threads of the neck portion and cap are free of each other,

d. cooperable stopper means on the cap and neck portion, for sealingly closing the latter when the cap is threaded fully thereon,

e. valve means for sealing the neck portion and cap to each other when the latter is in its retracted position, said valve means enabling discharge of liquid to occur between the neck portion and cap when the latter is out of said retracted position, and

f. floatation means on the cap, defining a float chamber when the cap is inverted and immersed in the liquid of a flush tank, for automatically shifting the cap from its extended to its retracted position in response to a rising level of said liquid, said cap shifting by gravity to its extended position as the liquid level falls.

2. A liquid dispenser as in claim 1, wherein:

a. said cooperable sealing means on the cap and neck portion comprises a resilient annular sealing lip adjacent the open end of the container neck, and

b. an annular ring-like sealing portion on the cap adjacent the threads thereof.

3. A liquid dispenser as in claim 1, wherein:

a. said floatation means comprises walls of the cap,

forming an inner chamber therein which is receivable in the neck portion of the container, and further comprises additional walls providing an annular outer chamber which surrounds the neck portion of the container.

4. A liquid dispenser as in claim 3, wherein:

a. said additional walls are spaced apart and are annular and concentric.

5. A liquid dispenser as in claim 1, wherein:

a. said screw cap has an annular guide portion,

b. said cooperable stop means comprising an internal annular bead on said annular guide portion, and c. a pair of spaced apart annular beads on said neck portion, cooperable with and straddling said internal annular bead of the cap guide portion.

6. A liquid dispenser as in claim 5, wherein:

a. said neck portion has longitudinally extending bearing ribs disposed between said spaced apart annular beads, said bearing ribs engaging the annular guide portion of the cap to prevent tilting when the cap moves between its extended and retracted positions.

7. A liquid dispenser as in claim 5, wherein:

a. said neck portion is constituted of yieldable plastic substance and the annular beads thereof can yield inwardly under external forces,

b. said cap bead being forcible past one of said beads of the neck portion so as to be straddled by said spaced apart beads,

c. said cooperable screw threads being capable of shifting the cap as it is turned, to force the bead thereof past said one bead of the neck portion.

8. A liquid dispenser as in claim 5, wherein:

a. one of said spaced apart beads on the neck portion is continuous and adapted to sealingly engage the bead of the cap to stopper the container,

b. said other of the spaced apart beads having a relieved surface to provide for passage of liquid between the cap and neck portion when it is engaged with the cap bead,

c. the distance between said spaced apart beads determining the volume of liquid which can flow from the container, and there-by constituting a metering control.

9. A liquid dispenser as in claim 8, wherein:

a. the relieved surface of the neck bead comprises a plurality of flats thereon,

b. said flats providing passages in the form of clearance spaces between the relieved-surface bead and the cap when the latter is out of its retracted position, whereby liquid from the container can flow.

between the said neck portion and cap.

10. A liquid dispenser as in claim 1, wherein:

a. the floatation means of the cap comprises concentric spaced apart annular walls thereof, surrounding the neck portion of the container,

b. said neck portion of the container having longitudinally extending bearing ribs engageable with the inner of said annular walls of the cap to constitute a guide means for preventing tilting of the cap when the latter moves between its extended and retracted positions.

11. A liquid dispenser as in claim 10, wherein:

a. the inner of said annular walls has an internal bead slidably engaged with said longitudinal bearing ribs.

12. A liquid dispenser as in claim 1, wherein:

a. said floatation means comprises an annular outer wall of the cap, and an annular inner wall of the cap, and

b. said annular walls defining an air chamber providing a buoyant force to said cap when it is immersed in liquid.

13. A liquid dispenser as in claim 12 and further including:

a. a transverse wall connected with said annular walls, all of said walls constituting said air chamber.

14. A liquid dispenser as in claim 13, wherein:

a. all of said walls are constituted of molded plastic substance.

15. A liquid dispenser as in claim 14, wherein:

a. said transverse wall has substantially the configuration of a disc.

16. A liquid dispenser as in claim 14, wherein:

a. said transverse wall has an annular configuration.

17. A dispenser comprising in combination:

a. a container constituted as a bottle having a top, discharge neck portion and having a bottom wall disposed oppositely to said neck portion,

b. said bottom wall having a groove extending transversely from one side of the container to the other,

c. said groove having opposite undercut side walls,

d. a side wall of the container adjacent the bottom wall having a recess communicating with said groove, and

e. a slide, clamp piece having a flat body portion disposed in the groove of the container bottom wall and slidable therein,

f. said clamp piece having respectively at its ends depending extremities forming with the flat body a U-shaped configuration,

g. one of said extremities being engageable with the wall of the recess in the container side wall when the clamp piece is slide in said groove to advance the other extremity away from the opposite container side wall,

h. said other extremity when so advanced being spaced from said opposite side wall to accommodate a support member from which the bottle can be suspended.

18. The invention as set forth in claim 17, wherein:

a. said first extremity makes an acute angle with the body portion of the clamp piece whereby the tip of said extremity effects the engagement between the same and said recess wall.

19. The invention as set forth in claim 17, wherein:

a. the length of the clamp piece is substantially equal to the width of the bottle measured parallel to the groove in the bottom wall thereof, whereby the clamp piece can be slid so that is extremities do not protrude substantially beyond the opposite side walls of the container.

20. The invention as set forth in claim 17, wherein:

a. the bottle is constituted of blow-molded plastic,

and

b. the clamp piece is constituted of formed sheet metal.

21. The invention as set forth in claim 17, wherein:

a. the side walls of the groove are yieldable to enable the body portion of the clamp piece to be forced broadside into the groove and retained by the undercut portions of the side walls of the groove.

22. The invention as set forth in claim 17, wherein:

a. the depth of the recess is commensurate with the spacing between said other extremity and said opposite side wall when the, first extremity engages the recess wall. 

1. A liquid dispenser for flush tanks and the like, comprising in combination: a. an inverted container having a bottom discharge neck portion provided with a longitudinal bore which communicates with its interior, said neck portion having external screw threads, b. a captive screw cap constituting a stopper, said cap being adapted for loose movement on the neck portion, said cap having internal screw threads cooperable and engageable with the external threads of the container neck portion, c. cooperable stop means disposed on said screw cap and container neck portion for restricting axial movement of the cap between extended and retracted positions on the neck portion wherein for both said positions the screw threads of the neck portion and cap are free of each other, d. cooperable stopper means on the cap and neck portion, for sealingly closing the latter when the cap is threaded fully thereon, e. valve means for sealing the neck portion and cap to each other when the latter is in its retracted position, said valve means enabling discharge of liquid to occur between the neck portion and cap when the latter is out of said retracted position, and f. floatation means on the cap, defining a float chamber when the cap is inverted and immersed in the liquid of a flush tank, for automatically shifting the cap from its extended to its retracted position in response to a rising level of said liquid, said cap shifting by gravity to its extended position as the liquid level falls.
 2. A liquid dispenser as in claim 1, wherein: a. said cooperable sealing means on the cap and neck portion comprises a resilient annular sealing lip adjacent the open end of the container neck, and b. an annular ring-like sealing portion on the cap adjacent the threads thereof.
 3. A liquid dispenser as in claim 1, wherein: a. said floatation means comprises walls of the cap, forming an inner chamber therein which is receivable in the neck portion of the container, and further comprises additional walls providing an annular outer chamber which surrounds the neck portion of the container.
 4. A liquid dispenser as in claim 3, wherein: a. said additional walls are spaced apart and are annular and concentric.
 5. A liquid dispenser as in claim 1, wherein: a. said screw cap has an annular guide portion, b. said cooperable stop means comprising an internal annular bead on said annular guide portion, and c. a pair of spaced apart annular beads on said neck portion, cooperable with and straddling said internal annular bead of tHe cap guide portion.
 6. A liquid dispenser as in claim 5, wherein: a. said neck portion has longitudinally extending bearing ribs disposed between said spaced apart annular beads, said bearing ribs engaging the annular guide portion of the cap to prevent tilting when the cap moves between its extended and retracted positions.
 7. A liquid dispenser as in claim 5, wherein: a. said neck portion is constituted of yieldable plastic substance and the annular beads thereof can yield inwardly under external forces, b. said cap bead being forcible past one of said beads of the neck portion so as to be straddled by said spaced apart beads, c. said cooperable screw threads being capable of shifting the cap as it is turned, to force the bead thereof past said one bead of the neck portion.
 8. A liquid dispenser as in claim 5, wherein: a. one of said spaced apart beads on the neck portion is continuous and adapted to sealingly engage the bead of the cap to stopper the container, b. said other of the spaced apart beads having a relieved surface to provide for passage of liquid between the cap and neck portion when it is engaged with the cap bead, c. the distance between said spaced apart beads determining the volume of liquid which can flow from the container, and there-by constituting a metering control.
 9. A liquid dispenser as in claim 8, wherein: a. the relieved surface of the neck bead comprises a plurality of flats thereon, b. said flats providing passages in the form of clearance spaces between the relieved-surface bead and the cap when the latter is out of its retracted position, whereby liquid from the container can flow between the said neck portion and cap.
 10. A liquid dispenser as in claim 1, wherein: a. the floatation means of the cap comprises concentric spaced apart annular walls thereof, surrounding the neck portion of the container, b. said neck portion of the container having longitudinally extending bearing ribs engageable with the inner of said annular walls of the cap to constitute a guide means for preventing tilting of the cap when the latter moves between its extended and retracted positions.
 11. A liquid dispenser as in claim 10, wherein: a. the inner of said annular walls has an internal bead slidably engaged with said longitudinal bearing ribs.
 12. A liquid dispenser as in claim 1, wherein: a. said floatation means comprises an annular outer wall of the cap, and an annular inner wall of the cap, and b. said annular walls defining an air chamber providing a buoyant force to said cap when it is immersed in liquid.
 13. A liquid dispenser as in claim 12 and further including: a. a transverse wall connected with said annular walls, all of said walls constituting said air chamber.
 14. A liquid dispenser as in claim 13, wherein: a. all of said walls are constituted of molded plastic substance.
 15. A liquid dispenser as in claim 14, wherein: a. said transverse wall has substantially the configuration of a disc.
 16. A liquid dispenser as in claim 14, wherein: a. said transverse wall has an annular configuration.
 17. A dispenser comprising in combination: a. a container constituted as a bottle having a top, discharge neck portion and having a bottom wall disposed oppositely to said neck portion, b. said bottom wall having a groove extending transversely from one side of the container to the other, c. said groove having opposite undercut side walls, d. a side wall of the container adjacent the bottom wall having a recess communicating with said groove, and e. a slide, clamp piece having a flat body portion disposed in the groove of the container bottom wall and slidable therein, f. said clamp piece having respectively at its ends depending extremities forming with the flat body a U-shaped configuration, g. one of said extremities being engageable with the wall of the recess in the container Side wall when the clamp piece is slide in said groove to advance the other extremity away from the opposite container side wall, h. said other extremity when so advanced being spaced from said opposite side wall to accommodate a support member from which the bottle can be suspended.
 18. The invention as set forth in claim 17, wherein: a. said first extremity makes an acute angle with the body portion of the clamp piece whereby the tip of said extremity effects the engagement between the same and said recess wall.
 19. The invention as set forth in claim 17, wherein: a. the length of the clamp piece is substantially equal to the width of the bottle measured parallel to the groove in the bottom wall thereof, whereby the clamp piece can be slid so that is extremities do not protrude substantially beyond the opposite side walls of the container.
 20. The invention as set forth in claim 17, wherein: a. the bottle is constituted of blow-molded plastic, and b. the clamp piece is constituted of formed sheet metal.
 21. The invention as set forth in claim 17, wherein: a. the side walls of the groove are yieldable to enable the body portion of the clamp piece to be forced broadside into the groove and retained by the undercut portions of the side walls of the groove.
 22. The invention as set forth in claim 17, wherein: a. the depth of the recess is commensurate with the spacing between said other extremity and said opposite side wall when the first extremity engages the recess wall. 